Crews battled a fire that caused major damage to a restaurant on the northwest side of Tucson early Sunday morning, June 25.

At around 1 a.m. crews responded to a fire at the Denny's diner at Oracle and River roads, according to the Northwest Fire District.

NWFD arrived to find heavy smoke coming from the building and began battling flames located in the interior of the restaurant. Officials said the fire extended into the attic space of the restaurant, which ultimately compromised the integrity of the roof.

Footage from last nights fire. Fire is now out but this complex will be closed through the early morning. Oracle/River NE quad. pic.twitter.com/PhgvfyXwd2

The restaurant was open at the time the fire started and had to be evacuated, NWFD said.

"The fact that everybody was able to evacuate on their own and get out of the building is a relief to us," NWFD Capt. Brian Keeley said.

On Monday, June 26, Keeley said fire investigators were unable to access the kitchen area of the restaurant, which is where the fire is believed to have originated based on statements from witnesses. Workers and patrons indicated that the fire originated on one of the stoves.

Keeley said the fire is considered accidental.

There were no rescues needed, and firefighters did not have to enter the building, which was destroyed.

Instead, firefighters waited and watched closely as they worked to put out hot spots late into the afternoon. They knew the destruction was extensive, and lives were affected.

"The workers, obviously, were concerned. This is their livelihood. This is their job. They were here when it happened," Keeley said.

Denny's District Manager Julie Malone-Green said 35 Denny's employees were displaced by the fire.

But Malone-Green said those employees won't be in limbo for long. She said they are already being "farmed out" to the six other Denny's diners that she manages around Tucson. She said there will be no need to re-train them.

Malone-Green said that they plan to rebuild the restaurant as soon as possible.

NWFD said 44 firefighters were at the scene battling this fire. It took them just under an hour to extinguish the main body of the fire, but they did not clear the Denny's parking lot until about 14 hours later.

Because of their continued work late into Sunday afternoon, the parking lot of the Denny's shopping center was closed to the public. It meant other businesses, normally open, had to stay locked up with no access to their stores.

"The driveways are blocked with debris, even to the extent that we don't want people pulling in here and driving over glass, and now you've got a bunch of popped, flat tires," Keeley said. "It just wouldn't be safe to let patrons for the other businesses in at this point, but that's certainly a priority for us, is to get this parking lot open as soon as possible."

Keeley said the fire likely started in the kitchen. He said he has no reason to believe that the fire was intentional, but investigators are still looking into the cause.

Dozens of people spent Wednesday afternoon putting the finishing touches on their wagons for the annual Tucson Rodeo Parade. There are a total of 81 wagons in this year's parade. Close to 2,400 people and 560 horses will be walking in the parade as well.

Dozens of people spent Wednesday afternoon putting the finishing touches on their wagons for the annual Tucson Rodeo Parade. There are a total of 81 wagons in this year's parade. Close to 2,400 people and 560 horses will be walking in the parade as well.